Second step. Evacuation. With the rush of aqueous which follows the incision some soft matter is usually evacuated; then a curette may be introduced, if necessary, and the lens fragments removed by gentle manipulation. Occasionally the iris may prolapse into the wound; if this happens it should be replaced, but if it occur more than once the prolapsed portion should be removed. Suction apparatus has been used for removing the soft lens matter, but it is not to be recommended in most cases, owing to the difficulty of sterilization and the trauma which it may cause. After-treatment as for needling should be carried out.
EVULSION OF THE CAPSULE
Indications. (i) In congenital cataract when the lens consists of little more than a dense capsular mass.
(ii) In dense capsular membranes following removal of a lens by discission in which a cutting needle cannot make a hole.
Instruments. Speculum, fixation forceps, keratome, capsule forceps, discission needle.
Operation. A general anæsthetic is usually desirable.
First step. The pupil is previously dilated with atropine. In the case of congenital cataract a discission needle is first passed into the mass to estimate its consistency. If it consist of little more than capsule an incision is made at the limbus with the keratome as described for evacuation.
Second step. The blades of the capsule forceps are then inserted closed, opened, and the opaque capsule grasped and withdrawn from the eye. The speculum is then removed and a pad and bandage applied. The pupil should be kept dilated with atropine subsequently, as a certain amount of irido-cyclitis following the operation is not infrequent. Occasionally the iris may become entangled in the wound, and it should then be removed.